Control mechanism



Dec. 29, 1942. M. B.. cAMRo-N 2,306,521

CONTROL MECHANISM Filed Aug. 28. i941- 2 sheets-sheet 1 Figi i i 8l 68 4e 4-7 6,8 e6

-k .4l @76a ,1. 45 2 i Gl /l 2 R F T y /32 f I4-32 2? Z7 3l Z7 v 3l Z8 2 so 55 I 35 so lq I3 [4 l5 ATTORNEY Dec. 29, 1942. -M. B. CAMERON CONTROL MECHAN'ISM Filed Aug. 28, 1941 2 Sheets-Sheet 2 m 4 e m Rm. 0,. 0 5.6 MB m mm 8 0H Y 4 oa 5., M md 7T Y F. 10...

[lll/IIA ATTORNEY vPatented Dec. 29, 1942 CONTROL MECHANISM Mortimer B. Cameron, Edgewood, Pa., assg'nor to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application August 28, 1941, Serial No. 408,568

6 Claims.y (Cl. 1in-'3.5)

'I'his invention relates to control mechanisms and more particularly to the type employing a switch mechanism which is manually operative to selectively control different operations.

In my copending application Serial No. 347,822, filed July 27, 1940, and which has matured on April 14, 1942, into Patent No. 2,279,365, there is disclosed a control system for a clutch and a selective forward and reverse transmission of a vehicle of the type adapted to be operated by an internal combustion engine. This system embodies a clutch control switch having a neutral position for disengaging theclutch and at either side of said neutral position there is a drive position for effecting engagement of the clutch parts to transmit power from the propelling engine through the transmission to the vehicle drive wheels.

One object of the invention is the provision of an improved system of the above type.

In the above control system the selective conditioning of the forward and reverse transmission is dependent upon energization of a transmission control wire which is connected to the clutch control switch in such a manner as to be energized only in the neutral position of the switch. By this arrangement the condition of the transmission cannot be changed while the vehicle is being propelled in a chosen direction and this is desirable to prevent damage tothe transmission, `to other parts of the power transmitting system or to the vehicle.

Another object of the invention is the provision of a novel manually operative selector switch which is particularly adapted though not limited in use for selectively controlling the conditioning of the transmission above described upon energization of the transmission control wire in neutral position of the clutch control switch.

When the clutch control switch is in. a drive 1 position to cause movement of the vehicle in a chosen direction, the supply of electric current to the transmission control wire is cut off. Under this condition movement of the transmission selector switch from. the position' which determines the direction of vehicle travel would therefore have no eiect upon the transmission, as will be apparent. However, assume that the selector switch were thus moved accidentally or otherwise, to a position for conditioning the transmission to provide for movement of the vehicle in the reverse direction, and that subsequently the clutch control switch were moved to neutral position to permit Acoasting of the vehicle down a grade.

Under such a condition electric current would be supplied tothe transmission selector switch and an undesired change in the condition of the transmission device would occur which might result in damage thereto or to other parts of the power transmission system or to the vehicle itself.

Another object of the invention is therefore the provision lof a transmission selector switch embodying means for automatically locking same against movement when the clutch control switch is in a chosen drive position and providing for adjustment of the transmission selector switch when and only when the clutch control switch is moved to its neutral position.

Unless insured against or prevented, there is even a possibility that the position of the transmission selector switch might become undesirably changed, due possibly to being struck or leaned against by the operator or another person, while the vehicle was coasting down a grade with the clutch control switch in neutral position in which case a change in condition of the transmission might o'ccur with disastrous results.

Another object of theinvention is therefore the provision of a transmission selecton switch which is so designed as to avoid accidental movement to a position for causing reversing of the transmission when the clutch control switch is in its neutral position.

Other objects and advantages will be apparent from the following more detailed description of the invention.

Description In the accompanying drawings; Fig. l is a diagrammatic view, partly in section and partly in outline, of a combined clutch and transmisl'sion control system embodying the improved transmission selector switch which is shown in plan; Fig. 2 is a sectional view of the transmission selector switch taken on the line 2-2 in Fig. 1; Fig. 3 is a sectional view of the selector switch taken on the line 3 3 in Fig. 2;'Fig. 4 is a side view of the selector switch shown in Figs. l to 3; Fig. 5 is a sectional view similar to Fig. 2 of a modified form of transmission selector switch and Fig. 6 is a partial plan View of the selector switch shown in Fig. 5 and having certain parts broken away to show interior construction.

In Fig. 1 thev reference numeral I indicates a portion of a clutch housing and the reference numeral 2 indicates a transmission housing. These housings are shown connected and the housing I is adapted to contain a clutch having two Vdrive positions and an intermediate neutral cr non-driving position, While'the transmission detailed description thereof therefore is not deemed essential to a clear understanding ofthe invention.

The reference numeral 3 indicates a clutch control switch comprising a manually movable switch member 4 which is mounted to turn on but is suitably insulated from a shaft 5 and which is constantly connected to one terminal of any suitable source of supply of electric current, such as a battery 6, the other terminal of which is grounded. The switch member 4 is provided for Vcontrolling the position of the clutch in the clutch housing I and has a neutral position, in which it is shown, for effecting movement of said clutch to its non-driving position. The switch member 4 is movable from its neutral position shown in either direction to one lor another of two driving positions 8 or 9 for supplying electric current from the battery B to various wires for moving the clutch to one or the other of its two drive positions.

In neutral position of the switch member 4 it provides an electrical connection between the battery 6 and a transmission control wire 1, while in both drive positions this connection is broken. This supply of electric current to the transmission control wire 1 is provided in order that the condition of the transmission 2 can be changed to obtain a desired direction of movement of the vehicle. The conditioning of the transmission 2 is .thus dependent upon .energization of the wire 1 and since this occurs only in neutral position of the clutch control switch member 4 it should be noted that the condition of the transmission cannot be changed except when the clutch in housing I is disengaged or is in its non-driving position. l

Since reference may be made to my copending application above referred to which discloses and describes in detail the arrangements whereby the conditioning of the clutch in housing I under the control of the clutch control switch 3 is obtained a further description of the above parts will be omitted in the present application.

Projecting through one side of the transmission housing 2 is a transmission control shaft I 0 which is rockable to two different positions to condition the transmission within the housing to provide for movement of the vehicle in either one direction or the opposite direction. For thus rocking the shaft I9 one end of an arm II is secured thereto. In thev drawing the shaft I0 and arm II are shown in the position which it may be assumed they will occupy to condition the transmission to provide for forward movement of the vehicle. To provide for reverse movement of the vehicle said shaft and arm may occupy a position such as indicated by the dash line I2.

Mounted on one side of the transmission housing 2 above the shaft Il) is a shifting engine I3 lwhich comprises a casing containing two pistons I4 and I5. These pistons are spaced apart and connected together for movement in unison by a rod I6. The arm II extends through a slot I1 in the casing and its inner bifurcated end straddles a pin I8 projecting from the rod I6 to provide an operating connection between the two pistons I4 and I5 and the transmission control shaft IIJ.

The piston I5 is shown in contact with one end of the casing to which position it is adapted to be moved by fluid under pressure supplied to a pressure chamber I9 at the outer face of piston I4 for rocking the arm II and shaft I0 to their forward drive positions shown. At the outer face of piston I5 is a pressure chamber 20 to which fluid under pressure is adapted to be supplied for moving the pistons in the opposite direction until piston I4 engages the opposite end of the casing for thereby rocking the arm II and shaft I0 to the reverse drive position indicated by the dotted line I2. This movement of the pistons I4 and I5 by fluid pressure supplied to either chamber I9 or 29 is dependent upon the chamber not being supplied with fluid under pressure being open to the atmosphere, as will be apparent.

The supply of fluid under pressure to chambers I9 and 2!) and the opening of said chambers to the atmosphere is adapted to be controlled by a forward electromagnet valve Ydevice 25 and a reverse electromagnet valve device 26, respectively. Both of these electromagnet devices may be of identical structure, each comprising a mag- .et and two oppositely arranged valves 21 and 28 which are contained in chambers 29 and 30 and which have fluted stems engaging each other in an intermediate chamber 3|. The chamber 29 in each of the two magnet devices is open to the atmosphere through a port 32 while the chamber 3l! in each is connected to a pipe 33 adapted to be constantly supplied-with fluid under pressure from any suitable source such as a reservoir 34. The chamber 3| in the magnet device.

25 is connected to chamber I9 in the shifting engine I3 and the corresponding chamber in the magnet device 26 is connected to chamber 29 in said shifting engine. When the electromagnet devices are energized, the valves 21 are adapted to be seated and the valves 28 unseated and when deenergized a coil spring in chamber 30 of each acting on the valve 28 therein is adapted to seat valve 28 and unseat the valve 21.

When either one of the electromagnets 25 or 29 is deenergized, the other is adapted to be energized as will be later brought out. Let it be assume-d that the electromagnet 26 is deenergized under which condition pressure chamber 29 in the shifting engine I3 Will be open past the valve 21 to the atmosphere. With the electromagnet 25 energized at this time the valve 28 will be unseated so as to supply uid under pressure from the reservoir 34 to pressure chamber I9 in the shifting engine I3 which pressure acting on piston I4 will move said piston and thereby the piston 20 and transmission shifting arm I I and shaft I0 to their forward drive positions shown. In order to move the transmission shifting arm II and shaft Ill to the reverse drive position indicated by dash line I2 the electromagnet 25 is adapted to be deenergized for opening the pressure chamber I9 to the atmosphere while the electromagnet device 26 is adapted to be energized for supplying fluid under pressure from the reservoir 34 to pressure chamber 20 for actuating the pistons I5 and I4 to their reverse drive position at the left-hand end of the shifting engine I3, as will be apparent.

Electric current for energizing the electromagnet devices and 26 is adapted to be obtained from the transmissionrcontrol wire. when, and only when, the clutch Ycontrol switch member 4 is in neutral position shown and this supply `of current is adaptedr to be selectively controlled to said electromagnets by a transmission control or reversing switch indicated generally by the reference numeral 40.

The transmission control switch 40 comprises two parallel arranged plate like members 4| and 42 which are spaced apart and formed integral with a rib'43 connecting one side of the plates and a rib 44 connecting the plates at the opposite side. The outer face of the plate 4| is adapted to be mounted against one side of a bracket member 45 which may be so located, as to position the selector switch for convenient operation by the operator of the vehicle. Mounted against the opposite side of bracket member 45 is an escutcheon plate 45. Screws 41 extending through plate. 46 and member 45 and having screw threaded engagement the plate like member 4| are provided for rigidly securing the switch to the member 45.

The members 4| 42 and 45 and the escutcheon platei46 are provided with aligned bores through ywhich extends a switch operating shaft l48. 'I'his shaft is journalled in the bore in member `4| and below said bore is provided with a shoulder 49 at the junction of the journaled portion and a portion 53 of smaller diameter. The lower end. of vthe shaft extending through the plate like member 42 is of smaller diameter than portion 50 to provide a shoulder 5| for engagement by a sleevelike bearing member 52 which is journaledy in the plate 42 and secured on the shaft by a nut 53 having screw-threaded engagement therewith.

Mounted on the shaft 48 between the` plate like members 4| and 42 is a switch operating cam 55 which is clamped by the. nut 53 between a washer 56 engaging the shoulder 49 and a quadrant 57 which is disposed between said cam and the bearing member 52. The cam 55 and quadrant 5l are secured against turning relative to the shaft 48 by means of a key 58 which is disposed in a slot in said shaft and extends into slots in said cam and quadrant. One purpose of the bearing ring 52 is to provide for assemblying of the key 58 to its working position shown and for then holding said key in such position.

An operating lever 6|] is mounted on the end of the shaft extending beyond thev escutcheon plate and is connected thereto by means of a pin 6| for turning said shaft to a forward posinger 19.

tion and to a reverse position indicated by the legends F and R shown on the escutcheon plate 4S in Fig. 1.

In the end oi lever B0 opposite that connected with the shaft 48 is a bore t2 formed with its axis parallel to that of the shaft 48. This bore is open at the end adjacent the. escutcheon plate 46 and closed at its opposite end and extending through said bore and a suitable bore in the closed end thereof is a plunger 63. A washer is secured by a nut 66 to the end of the plunger projecting beyond the closed end of bore 52. Within the bore 62 adjacent the open end thereof the plunger is provided with a guide portion 64 between which and the closed end of the bore Y is interposed a coil spring 61 which is under compression and therefore effective to urge the plunger in the direction of the escutcheon plate 46 ln each of the forward and reverse positions 75 of the lever the escutcheon plate is provided with a bore 68 into which the end of plunger 63 is adaptedy to beforced by the spring 61. In

order to move the lever Sli from one of its positions to the *other the plunger 63 must be first manually withdrawn from one or the other of the bores 68 and to accomplish this the. operator must grasp the washer 65 and draw the plunger f out of said bore against the force of the spring 61.

Extending upwardlyfrom the plate like member 42 are two projections 69 and 10 arranged to be engaged by the opposite sides of the quadrant 5'! in the two different operating positions of the lever E@ for limiting movement of said lever and thus defining said operating positions. The bores 68 are located to receive the plunger 63 in the positions dened .by contact between the quadrant 5'! and the projections 69 and l0. v

At one side of the shaft 48 the two members 4| and 42 are provided with like outwardly extending portions ?3 arranged one above: the other and carrying on their opposite ends`v two bars 'I4 which are preferably made of material non-conductive to electricity. A like pair of bars 'l5 and 75 are carried by spaced parts of the plates 4| and 42 at the opposite side of the shaft 48. A contact finger 'Il extends past one side of the cam 55 with one end disposed adjacent the v switch device 3 and by an electrical connector 82 to the screw 8f3 whereby both of the exible con-- tact ngers Tl and i9 are connected with the transmission control wire 1.

The Contact bar l5 carries a screw 83 having on one end a iixed contact 54 aligned for engagement by the adjacent movable end of the contact finger Tl'. The screw 83 is also connected to an electrical conductor S5 which leads to one terminal of the magnet of the electromagnet device 25, the other terminal of which is grounded.

The Contact bar i5 carries a screw 8E having on one end aiixed contact Si .aligned for engagement by the adjacent end of the flexible contact This screw is connected to'an electrical conductor 83 which leads to one terminal of the magnet of the reverse magnet valve device 26, the other terminal of which is grounded.

The two contact fingers l? 'le are made of resilient material and are stressed'so as to be constantly urged into Contact with diametrically opposite portions of the cam 55. The cam has a lobe 5 adapted upon engagement with either one or the other of the two contact .fingers to deflect same into contact with he respective fixed contact 84 or 8l. When the lobe 95 is out of contact with the fingers, said fingers are adapted to spring out of contact with their respective fixed Contact 84 or Si. with respect to the operating handle 6! 'that when said handle is in the forward position, as shown in Fig. l, the contact finger 'il will be in engagement with the Contact 54, as shown in 3, for thereby connecting the transmission control wire 'l to the forward electrcinagnet device 25. When the operating handle is in its other or reverse position, the lobe Sii is adapted to be positioned for holding the contact finger i in engagement with the xed contact t? to thereby This lobe is so arranged connrect the reverse electromagnet device 25 with the transmission control wire 1, it being noted that when either of the contact ngers is in engagement with its respective fixed contact, the

other contact finger opens the circuit controlled thereby.

Thus whenever the clutch control switch meinber 4 is in neutral position shown causing disengagement of the clutch on the vehicle supplying electric current to the transmission control wire 1, the operator by moving the handle 60 of the transmission selector switch itl to either its forward position or reverse position, as desired, may selectively control the energizaton and deenergization of the electromagnet devices 25 and 25 to cause the shifting engine i3 to rock the arm I I and shaft It to a selected position for providing movement of the vehicle in the desired direction upon subsequent movement or the clutch control switch member 4 to one or the other oi its driving positions 8 or E3. It will be noted that this selective conditioning of the transmission control arm Il and shaft lli is obtainable only when electric current is supplied to the control wire 1 and thus only when the clutch on the vehicle is in its disengaged position.

The rib 44 connecting the plate like members 4i and 42 of the transmission selector switch extends below the plate like member 42 and to its lower end the end of a leg 9i of a L-shaped bracket 92 is secured by screws 93. The other leg 94 of the bracket 92 extends upwardly in the direction of the plate like member 42.

The bracket 92 is provided for carrying a lock magnet comprising a coil 35 which is secured to the leg SI by a core 96 having screw-th ,.de'd engagement with the leg. The two terminals of the coil 95 are connected by leads 31, to adres 9B and 99 connected respectively to the transmission control wire 1 and to ground as shown in Fig. l.

An armature IEI is disposed above the upper end of the core gli with one end extending over` the end of the bracket leg 94 while the other end extends into a cavity 02' provided in the rib 44 below the plate like portion i2 of the switch. In the end of the armature Ii disposed above the bracket leg 94there are provided two elongated openings iil and through each of these openings a pin iMeXtends and is secured to the bracket leg 94. The head of these pins are spaced slightly from the adjacent side of the armature IIli and this together with the elongated openings |93 provide for rocking movement of the armature IE! in a direction toward and away from the magnet core 95.

A bushing IBB is mounted in a suitable bore in the plate like member 42 and has at its lower end a collar IIl1 engaging the lower face of said member and adapted to be contacted by the armature IIil when the magnet coil 95 is deenergized. A lock pin |88 is mounted to slide in a bore through bushing IE5 and extends through a slot Il@ provided in the free end of armature I0 I Below the armature the pin II!8 has a head H29 of greater size than slot Il!) so that movement of the armature in the direction of core 96 will move the pin lll in the same direction. A coil spring III contained in cavity EQ2 of leg 44 is supported at one end on the closed end wall of said cavity While the opposite end bears against the head IDS of the lock pin |08. This spring is adapted to urge the lock pin |08 and armature IBI to the position shown in Fig. 2 when the magnet coil 95 is deenergized. When the coil 95 is energized to attract the armature IUI in the direction of core 9S said armature is adapted to move the pin II8 against spring III to a position in which the upper end of the pin is spaced from the lower face of the quadrant 51.

The quadrant 51 is provided with two notches II2 and II3 and the pin Hi8 is so arranged as to enter these notches under the action of spring III when the operating handle a is in the forward and reverse positions, respectively.

Since the magnet coil is connected to the transmission control Wire 1 and therefore adapted to be energized only when the clutch control switch member 4 is in neutral position, it will be noted that with the clutch control switch member 4 in either drive position 8 or 9, the spring III will be effective to hold the lock pin I08 in either notch II2 or IIB of the switch quadrant 51. Thus with the clutch on the vehicle engaged, the lock pin H33 will prevent movement, either accidental or otherwise, of the transmission control switch 4I) out of the positionk determining the direction of vehicle movement. By thus locking the transmission selector switch 4B against movement while propelling the vehicle an undesired change in condition of the transmission cannot occur, with possible disastrous results, in case the operator should move the clutch control member 4 to its neutral position in order for instance to coast down a grade.

While coasting with the clutch control switch member 4 in neutral position it will be noted that electric current is supplied to the transmission control wire 1, but obviously it would not be desired to change the condition of the transmission at this time. To prevent such a change from being effected accidentally, as by the operator leaning against or striking the transmission selector switch handle 60, the locking pin 53 in said handle is provided. This pin insures against such accidental movement of handle $0, since it is necessary for the operator to grasp the washer 65 and withdraw the locking pin 63 from one or the other of the bores 68 in the escutcheon plate 46 in order to eiect such movement. Thus a conscious or intentional act on the part of the operator is required to change the position of the transmission selector switch 40, due to which any change of the transmission during coasting for instance cannot accidentally occur.

The improved selector switch 40 thus provides for selective conditioning of the transmission when the clutch control switch member 4 is in neutral position causing disengagement of the clutch on the vehicle. The locking pin |08 insures that the position of the transmission selector switch 40 will not be changed while the clutch control switch member 4 is in either of its drive positions so as to thereby eliminate the possibility of disaster to the vehicle or parts thereof upon subsequent movement of the clutch control switch member to neutral position. The plunger 63 in the operation handle 64 prevents an accidental change in the condition of the transmission when the clutch c'ontrol switch member 4 is in neutral position so that while the vehicle is under motion damage to any part thereof cannot unintentionally occur.

The condition of the transmission should not be changed except when the vehicle is at rest, at which time the clutch switch member 4 will be in neutral position and the transmission control wire 1 will be energized. To change the condition of the transmission at this time the operator Ymerely has to graspV the washer 65 conthen let go of the washer 65'and the spring 61' Vwill move the plunger63 into the aligned bore 68 in the" escutcheon plate to thereby `hold the selector switch in the desired adjusted position' .until a subsequent and conscious intended act 'by the operator.

Description of Figs. and .s

The embodiment of the invention disclosed in Figs. 5 and 6 differs from that above described in the following respects:

l' A plain operating handle |20 is secured to the operating shaft 48 for turning the switch device to its diflerent operating positions. In this hand1ethere is no locking plunger, such as the plunger 53 employed in the handle 60, and the `escutcheon plate 4'5 is not used. The handle |20 is preferably provided with a `pointer 12| which in each of the operating positions of the handle is adapted to cover an index member |22 which' is provided on the supporting bracket member 45 to indicate to the operator the operating position of the handle. The bracket member 45 may be provided under the handle `|21 with Ylegends F and R adjacent the index members |22 as av further aid to the operator for choosing the desired operating position.

, In addition to the above, a spring pressed detent 23 is slidablymounted in a suitable bore provided through the plate like memberr 42 between the locking plunger |08 and the bore in which the shaft bearing member '52 operates. 'This detent is urged in kthe direction of the underside of the quadrant A51 which is provided with two recesses |24 adapted to receive said detent in the forward and reverse positions of handle |20. A Ythird 'recess '|25 may, if desired, be provided intermediate the two" recesses |24 for receiving the detent |23 Yin a neutral position of the operating handle V|20 'intermediate the forward and reverse positions and in which lthe cam '55 will be so positioned that both of the switch lfingers 11 and 19 will open the circuits controlled thereby. On the upper face of the bracket 4'5 an index member '|26 may be provided, intermediate the two index members |22, for indicating the neutral position vof the handle |20 and the legend N may be placed on the member v45 adjacent the index member |26 'for theoperators convenience. The quadrant 51 may also be providedl with aV notch |21, located intermediate vthe vnotches ||2 and H3, vfor receiving the plunger |08 in the neutral position Yof the handle |20. f

The engagement of the detent '|23 in either of the recesses |24 provided in the underface of the quadrant 51 is adapted to resiliently oppose movement of the operating handle |20 out of each of its lextreme operating positions, due to which the attention ofthe operator willbe somewhat focused upon the operation of the device to thereby 'insure that the handle |20 will be moved to the desired position. The interengagement between the detent |23 and .any one of the recesses is also adapted to resiliently hold the switch :in a selected position when the lock pin I 08 is withdrawn from 'the quadrant 5.1. Furthermore, when the vehicle is coasting at which time the lock'pin |08 will be withdrawn .from the quadrant the interengagement of detent V|23 with 'the quadrant willY tene tonele` lthe vinnere .|20 against .accidental movement. In casethe handle .|.2sho`uld 'be unintentionally struck and shifted out of a drive'po'sition at,r this time, however, the detent |23 will enter Arecess l|25 and,

vthere'by'tend to arrest said handle and prevent continued'movement tothe other ldrive positiony which would undesirably condition the trans-` mission to provide for movement ofthe vehicle in the direction opposite `that .being traveled. The purpose of notch |21 infquadrant 51 is to prevent, while the vehicle is being propelled, accidental movement .of the handle |20 from a selected driving position to the rvother `driving .position in case the `handle hasnot been previously moved to the selected drive position toa suiiicient degree ltoplermit the 'locks pin A|08 to enter the notch 'I'i or notch'|.|3.` Under such a circumstance .if `handle |20 should be acciden- .tally struck it would be moved away from'the selected drive position Vinthe direction of the opposite drive position. However, such move- ,ment would 'bearrested 'in the neutral position by the entry of plunger .|08 into the notch |21 vas such notch `becomes aligned with saidv plunger, so as to thereby prevent accidental reversing of the transmission under su'ch a remote condi tion. v

. :Summary `ByY the use of eitherof the selectorswitch devices above described injcombination with thev switch the locking magnet `device including the Acoil 95 and the lock `pin |08insures that the switch will not be moved yaccidentally ,or otherf Wise from a selected drive position while the vehicle is vin motion, so as to thereby vprotect the propulsion system .as well`as other -parts of the vehicle against possible damage. The spring pressed Aplunger ki553 4in `the embodiment shown Yin Figs. l to 4 and the spring pressed detent |23 in theembodiment shown inligs 5 and 6, 'both act Ito prevent unintentional movement of the Vselector switch `from a chosen operating "position tov the other operatinglposition while the vehicle is in motion with the clutch control switch 3jin its neutral position. The plunger '63 .in `handle 6i! constitutes a positive means to prevent unintentional or accidental movement of the transmission selector switch since it requires va, conscious act on the part of the operator. The detent |24 does not act in the same positivemanner as plunger 63 to pre- .vent accidental movement of the switch handle, as ywill be apparent, but said detent ldoesprovide such a .resistance tomovement of ythe handle |20 as to call the operators attention to what is taking place so .as Vto. prevent an unintended change in Vthe'position ofthe handle. y Having now described `my invention, what I claim as new and desire to `secureby Letters Patent is in combination, `manually .operative clutch control'means having two clutch driving positions out of a selected position for rendering such clutch effective to transmit power and having a normal position between said driving positions for rendering said clutch ineffective to transmit power, transmission control' means for selectively conditioning said Atransmission to provide for either forward movement of the vehicle or movement in the reverse direction and comprising a manually operative selector device movable to a forward position and to a reverse position, movement of said selector device being dependent upon a chosen condition of a control medium, said clutch control means controlling said control medium and providing said chosen condition only in the normal position of said clutch control means, and means con- K trolled by said control medium and operative when said control medium is in other than said chosen condition for locking said selector device against movement.

2. A vehicle clutch and forward and reverse power transmission control system comprising in combination, manually operative clutch control means having two clutch driving positions for rendering such clutch effective to transmit power and having a normal position between said driving positions for rendering said clutch ineffective l -1 to transmit power, transmission control means for selectively conditioning said transmission to provide for either forward movement of the vehicle of movement in the reverse direction and comprising a manually operative selector device ,movable to a forward position and to a reverse position, locking means for securing said selector device against movement, means controlled by said clutch control means and operative in the normal position thereof to operate said locking means to release said selector device for manual movement, and means operative upon movement of said clutch control means out of said normal position to actuate said locking means to secure said selector device against movement.

3. A vehicle clutch and forward and reverse transmission control system comprising in combination, manually operative clutch control means having twoV clutch driving positions for rendering said clutch effective to transmit power and having a normal position between said driving positions for rendering said clutch ineffective to transmit power, selector means for selectively conditioning said transmission to provide for either forward or reverse movement of the vehicle and comprising a manually operative selector device having a forward position and a reverse position, means for locking said selector device against movement, a magnet operative upon energization to actuate said means to release said selector device for movement, said clutch control means in said normal position effecting energization of said magnet and in said clutch driving position deenergization of said magnet.

4. A vehicle clutch and forward and reverse transmission control system comprising in combination, a manually operative clutch control switch having a clutch driving position for rendering said clutch effective to transmit power and having a normal position for effecting disengagement of said clutch, an electric current supply wire, said manually operative clutch control switch supplying current to said wire in the normal position thereof and cutting off the supply of current to said wire in said clutch driving position, electrically controlled means for selectively conditioning said transmission, a manually operative selector switch having one position for supplying current from said wireto said electrically controlled means to effect the operation thereof to condition said transmission device to provide for forward movement of the vehicle and having another positionfor supplying current from said wire to saidV electrically controlled means to effect operation thereof 'to condition said transmission to provide for reverse movement of the vehicle, and electro-magnetically controlled means associated .with said selector switch and operative upon deenergization tolock said selector switch against movement and upon energization to release said selector switch for movement, said electro-magnetically controlled means being connected to and controlled from said wire.

5. A vehicle clutch and forward and reverse transmission control system comprising in combination, a manually operative clutch control means having a clutch driving position for rendering said clutch effective to transmit power and having a normal position for effecting disengagement of said clutch, a transmission control wire connected to said manually operative clutch control means and supplied with electric current in the normal position thereof, said manually operative clutch control means cutting oir the supply of current to said transmission control wire in said clutch driving position, electrically controlled means for controlling the positioning of said transmission including means operative upon the supply of current to a forward wire to condition said transmission to provide for forward movement of the vehicle and upon supply of electric current to a reverse wire to condition said transmission device to provide for movement of the vehicle in the reverse direction, a manually operative selector switch to which all of said wires are connected and being movable to one position for connecting said transmission control wire to said forward Wire and to another position for connecting said transmission control wire to said reverse wire, the forward or reverse wire not connected to said transmission control wire in said positions of said selector switch being deenergized, a locking member associated with said selector switch operative to secure same against movement, a magnet operative upon energization to release said locking member from said selector switch to provide for movement thereof, said magnet being connected to said transmission control wire, and spring pressed means associated with said selector switch operative to define the different positions thereof and to resiliently oppose movement of said switch out of said positions.

6. A vehicle clutch and forward and reverse transmission control system comprising in combination, a manually operative clutch control means having a clutch driving position for rendering said clutch effective to transmit power and having a normal position for effecting disengagement of said clutch, a transmission control wire connected to said manually operative clutch control means and supplied with electric current in the normal position thereof, said manually operative clutch control means cutting off the supply of current to said transmission control wire in said clutch driving position, electrically controlled means for controlling the positioning of said transmission including means operative upon the supply of current to a forward wire to condition said transmission to provide for forward movement of the vehicle and upon supply of electric current to a reverse Wire to condition said transmission device to provide for movement of the vehicle in the reverse direction, a manually operative selector switch to which all of said wires are connected and being movable to oner position for connecting said transmission control wire to said forward wire and to another position for connecting said transmission control wire to said reverse wire. the forward or reverse wire not connected to'said transmission control wire in said positions o1 10 said selector switch being deenergized, a locking member associated with saidselector switch opy erative to secure same against movement, a magnet operative upon energization to release said locking member :from said selector switch to pro- 15 vnecteci with said plunger adapted to be grasped by the fingers of an operator for releasing said plunger from said xed part to provide for movement of said handle to its diierent positions. MORTIMER. B. CAMERON. 

